In general usage are portable mobile telephones (in German usually called "handy" because they can be operated with one hand) and a large number of small size devices as pocket calculators, data bases and electronic notepads which can be carried along for personal usage due to their very small dimensions. Personal computers with displays that produce texts or graphics are known in the size of laptops or notebooks. But even these still have a size of DIN A 4 (German standard paper size) and are rather heavy.
A similar, portable device that can be used as a personal computer and for telecommunication is known from the EP 0 472 361 B1. It comprises a personal computer member and a mobile telephone being integrated into one housing which also contains a keyboard member for operating both the computer and the mobile telephone. A lid which covers a display when it is closed is pivoted on the housing. The lid is shaped in such a way that in its open position it leaves accessible a part of the display and also at least some of the keys of the keyboard member so that the device can be used in its function as a mobile telephone. The microphone for the telephone member and the speaker are situated on one of the long sides of the housing.
The disadvantage of the above mentioned device described in the EP 0 472 361 B1 is that it can not be used in the same way as usual mobile telephones of the type of a hand-held telephone because the arrangement of the keys for operating the telephone as well as the arrangement of the microphone and the speaker are different in comparison with other mobile telephones. Particularly, it is not possible to operate the telephone member of the deice with only one hand, as it is characteristic for mobile telephones of the type of a hand-held telephone, because in order to operate the telephone the deice has to be turned at first by 90.degree. with respect to its longitudinal axis and after that by 90.degree. with respect to its transversal axis.
In respect of its functions this device can not be extended, and it is not possible to connect additional power modules to it that would provide for a longer run.
In the DE 41 08 169 A1 a telephone was published which represents a mobile communication device that can be operated as a mobile radio telephone in connection with a personal computer and data transfer.
Another device which can either be carried along or be installed in a vehicle consists of a computer with a keyboard and a send-receive unit for a radio telephone or a car telephone and comprises a flap, similar to that of a laptop, on the front part of which there is a display. On the back side of the flap there is a holder for a hand-held telephone which on one side juts out with respect to the flap. When the flap is closed it covers the computer keyboard and the hand-held telephone is accessible and can be taken off. The keys for the telephone and for operating the computer which are situated on the upper side of the telephone are accessible. If the flap is lifted and forms a specific angle with the rest of the housing the computer keyboard is accessible and the mouthpiece and earpiece of the telephone being fixed to the back side of the flap are in front of a person looking in the direction of the display. This way the sound waves can without hindrance communicate between the user and the earpiece and mouthpiece of the telephone.
The disadvantage of this solution is that it is not possible to use this device as a mobile telephone. It has from the beg been developed as a device comprising two completely separate parts (a hand-held telephone and a laptop) being linked together. Also, as a result of its jutting out parts this device is highly sensitive to shock, especially in the case when it falls down.